We propose to complete an investigation of the subchronic toxicity of sulfite, including effects on reproduction, utilizing a sulfite oxidase-deficient rat model. Further research concerning the statistical signficance and etiology of mammary adenocarcinomas which developed during our experiments will be undertaken. Identification of the specific molecular sites of disulfide bond sulfitolysis in aortic tissue will be attempted and the effects of this reaction on the mechanical properties of the aorta will also be investigated.